Python Methods vs. Functions: Understanding the Differences and When to Use Classes

In the world of programming, Python is loved by programmers all over the world because of its simplicity and versatility. While using Python, you often use several terms like ‘method’, ‘function’, and ‘class’. In the beginning these terms may confuse you but, they play a vital role in coding.

Function and Method: What’s the Difference?

So, the question is what is the difference between function and a method? Function: a block of code that can be used again & again, performs a specific task.in other words, you can use it for certain actions whenever you wish to. On other hand, Method is associated with an object and data associated with it. 

Confuse? So, assume function as a general tool while method as specific tool that loves object and data associated with it. Let’s take an example. A function that is add_numbers(x,y) and it adds two numbers. You can use it anywhere in coding. But if you are using an object like calculator and its method is considered add (self, x,y) so you can understand that it will be done in the object that is Calculator.  

Why Use Classes in Python?

Use classes in Python as they are the foundation in object-oriented programming, and they also help to bundle data (attribute) and function (method) into one unit. So, why use classes in Python?

Modularity: The Classes help to organize your code into logical units; so, it becomes easy to manage and maintain the codes. In other words, each class represents a new concept or an entity of real life. You are able to create multiple instances (objects) with unique data in class.

Modularity is a technque which dividing your code into separate, independent modules that can be developed, tested, and maintained separately.

In this example we will create two types of geometric shapes: circles and rectangles. We’ll create separate modules for each shape. Here is an example.

  1. Create a file call ‘circle.py’ for the circle module:
				
					# circle.py

import math

def calculate_area(radius):
    return math.pi * radius**2

def calculate_circumference(radius):
    return 2 * math.pi * radius

				
			
  1. Create another file  ‘rectangle.py’ for the rectangle module:
				
					# rectangle.py

def calculate_area(width, height):
    return width * height

def calculate_perimeter(width, height):
    return 2 * (width + height)

				
			

Now, create a main file ‘main.py’ this file will use these modular components. 

				
					# main.py

import circle
import rectangle

# For circles
radius = 5
circle_area = circle.calculate_area(radius)
circle_circumference = circle.calculate_circumference(radius)
print(f"Circle Area: {circle_area:.2f}")
print(f"Circle Circumference: {circle_circumference:.2f}")

# For rectangles
width = 4
height = 6
rectangle_area = rectangle.calculate_area(width, height)
rectangle_perimeter = rectangle.calculate_perimeter(width, height)
print(f"Rectangle Area: {rectangle_area}")
print(f"Rectangle Perimeter: {rectangle_perimeter}")

				
			

Reusability: You can create many objects after defining class. It saves time by avoiding code duplication issues and reusability.

Here’s simple concept of reusability in Python using classes and objects. We’ll create a class that representing a Person and how you can create multiple objects of that class to achieve reusability.

				
					class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    
    def greet(self):
        print(f"Hello, my name is {self.name} and I am {self.age} years old.")

# Creating objects using the Person class
person1 = Person("Ahmed", 25)
person2 = Person("Tahir", 30)
person3 = Person("Sajjad", 22)

# Calling the greet method on each object
person1.greet()
person2.greet()
person3.greet()

				
			

Encapsulation: Classes allow you to encapsulate data and methods.  It also allows to hide internal detail of a method as it shows you a simple interface. By this step, your security is improved, and it also results in no unintended modifications.

Here’s a simple example of encapsulation using a ‘BankAccount’ class:

				
					class BankAccount:
    def __init__(self, account_number, balance):
        self._account_number = account_number  # Protected attribute
        self._balance = balance  # Protected attribute
    
    def get_balance(self):
        return self._balance
    
    def deposit(self, amount):
        if amount > 0:
            self._balance += amount
            print(f"Deposited {amount}. New balance: {self._balance}")
    
    def withdraw(self, amount):
        if 0 < amount <= self._balance:
            self._balance -= amount
            print(f"Withdrew {amount}. New balance: {self._balance}")
        else:
            print("Insufficient balance")

# Creating a BankAccount object
account = BankAccount("123456789", 1000)

# Accessing attributes directly (not recommended, but possible)
print("Account number:", account._account_number)  # Not recommended
print("Balance:", account._balance)  # Not recommended

# Using methods to interact with the object
print("Initial balance:", account.get_balance())
account.deposit(500)
account.withdraw(200)
account.withdraw(2000)

				
			

When to Use Classes in Python?

Are you wondering when to use classes in Python? Here are few scenarios where using classes is more beneficial for everyone who use it:

Complexity: when you write the  code it becomes complex and very difficult to manage your code, then classes provide you a structured way to break down into manageable components.

Related Data and Actions:

Classes also help you to  maintain clear connection between data and operations that manipulate data very closely related.

Modeling Real-world Concepts: If you want to create a model which is related to our real life e. g: person, car, or anything, use the classes as they have a natural and intuitive approach.

Code Reusability: If you want to write the same function and use it for different parts of your code, in this scenario class can be useful to encapsulate that functionality.

In summary, effective programming in Python programming you need a clear understanding of the difference between functions, methods, and classes. and how Classes can be helpful to enhance your coding skills and organize, reuse and maintain the code.  Wish to create actual or real-life models, use classes and that is why they are powerful tools in Python.

2 thoughts on “Python Methods vs. Functions: Understanding the Differences and When to Use Classes”

Leave a Comment